Circleguard

* add `fuzzy_mods` utils method, which allows you to pass a required mod and a list of optional mods, and a list of each possible mod combination is returned
* require snaps to also be in the hitwindow of a hitobj to be counted when using `only_on_hitobjs=True`
* Previously, snaps could be counted when they were "on" the closest hitobj, even though that hitobj might be many seconds in the past or future
* move to [osrparse](https://github.com/kszlim/osu-replay-parser) for osr parsing instead of [circleparse](https://github.com/circleguard/circleparse)

* require `slider>=0.4.0` instead of `slider~=0.4.0`

* add `only_on_hitobjs` parameter to `cg.snaps` (defaults to `True`) which, if set, only returns snaps that occur on hitobjects
* all hitobjects returned by `Circleguard` methods (from `cg.snaps` and `cg.hits`, for instance) are now converted to their hard_rock form if the replay had HR enabled
* add convenience method `cg.beatmap(replay)` which returns the beatmap associated with the given replay
* expose hitobject classes in `__init__.py`

* fix maps with no replays for a mod combo throwing `NoInfoAvailableException`
* required `slider ~= 0.3.1` instead of `slider == 0.3.1`

* remove `Mod.__ne__` as it's the inverse of `Mod.__eq__` by default if ne doesn't exist

- return ndarray instead of list in `Circleguardframetimes`
- add `Circleguardframetime_graph` to generate a frametime graph from a replay. This requires that you have `matplotlib` installed
- add `__str__` and `__repr__` to `Hit`
- fix ur and hits erroring on maps that have catmull sliders